Every door and doorway serves a purpose, closing off one area from another but acting as a way to pass between those areas. So as we put a door on a wall, we have to ask why it’s there. Was it designed to be used once or very rarely? Was it intended to be used frequently? Was it meant to be left open and only closed on rare occasions? Was it made as a distraction?

We start by deciding whether the door was meant to keep things in or keep things out. That particular fact has all sorts of interesting effects on story and encounter design. Depending on which case is applicable, the door may be more or less secure on the side the PCs start on. And if they close it behind them, what happens?

To do this, we flip a coin or roll your favorite die to determine odd or even. If it’s heads or odd, the door was meant to keep something in. If it was tails or odd, it was meant to keep something out.

Once you know why a door was put in, you can focus on what it was meant to keep in or out. Was it purely for security reasons? To lock something or someone in a cell or keep someone outside the front door? Or was it merely to confuse or entertain? Perhaps there’s an entire hallway of doors exactly the same and only one or two really open?

Pull out a d10 and roll here:

Noise

Starting

Safety

Security

Decoration

Distraction

Ceremony

Light or Air

Concealment

Convenience

We can come up with a few examples right away…

(In – Noise) This door has been soundproofed. No noise will pass to the outside.

(Out – Security) This door has been secured to keep something on the other side. It has likely been reinforced and stabilized.

(In – Decoration) This door was not designed to be opened and is merely a decoration in this place.

(Out – Ceremony) This door has not only been designed to keep you out, but there is a particular series of steps you must take before it may be opened.

(In – Light) There might be bright light on the other side of the door, but you cannot see it from the outside.

(Out – Convenience) This door is just a formality. It is designed to open and close quickly.

This is just the first step in figuring out the story behind your door… Who knows what the other steps might bring?